fix arch name in macos

lib/utils.bash

@@ -42,10 +42,19 @@ download_release() {
 	filename="$2"
 
 	# TODO: Adapt the release URL convention for rye
-	machine=$(uname -m)
-	os=$(uname -s | tr '[:upper:]' '[:lower:]')
+	arch=$(uname -m)
+	os=""
+	uname=$(uname -s | tr '[:upper:]' '[:lower:]')
+	if [ "$uname" -eq "linux" ]; then
+		os="linux"
+	elif [ "$uname" -eq "darwin" ]; then
+		os="macos"
+	else
+		fail "Unsupported OS: $uname"
+	fi
+
 	# https://github.com/mitsuhiko/rye/releases/download/0.3.0/rye-aarch64-linux.gz
-	url="$GH_REPO/releases/download/${version}/${TOOL_NAME}-${machine}-${os}.gz"
+	url="$GH_REPO/releases/download/${version}/${TOOL_NAME}-${arch}-${os}.gz"
 
 	echo "* Downloading $TOOL_NAME release $version..."
 	curl "${curl_opts[@]}" -o "$filename" -C - "$url" || fail "Could not download $url"